Electric haircutting appliances are generally known, and include trimmers, clippers and shavers whether powered by main supplied electricity or batteries. Such devices are generally used to trim body hair, in particular facial and head hair to allow a person to have a well-groomed appearance.
Commonly, conventional devices for cutting hair comprise a main body forming an elongated housing having a front or cutting end and an opposite handle end. A cutting blade assembly is disposed at the cutting end. The cutting blade assembly usually includes a stationary blade element and a movable blade element which moves in a reciprocal manner against the stationary blade element. The cutting blade assembly itself extends from the cutting end and is usually fixed in a single position relative to the main body of the hair clipper, such that the orientation of the cutting blade assembly is determined by a user orientating the main body of the device.
Since there is a great user demand for a hair clipping systems that offer the possibility to be used for different haircut lengths, many known hair clipping systems make use of separate, differently sized comb attachments. These comb attachments are generally mounted to the cutting end of a conventional hair clipping device to position the cutting blade assembly relative to the skin. In other words, such a comb attachment is used as a guide that moves over the skin and guides hair towards the cutting element. Typically, these comb attachments are mounted over the cutting blade assembly and spaces the cutting blades away from the surface of the skin from which the hairs extend.
In order to adjust between different possible cutting lengths the comb attachments may be movably mounted on the hair clipper. Users may thus shift the comb attachment between different positions leading to different haircut lengths. Usually these moveable comb arrangements may be adjusted between haircut lengths of 3 mm, 5 mm, 7 mm, 9 mm, usually up to 10 mm. These systems, however, include the disadvantage that they only allow for haircut lengths of 2.5 mm or 3 mm and above, since these lengths are usually the smallest lengths that can be reached with the comb attachment in its shortest position. Of course, the user may also use the hair clipping device without comb attachment, usually leading to a haircut length of 0.3 mm. However, haircut lengths in between these limit ranges, i.e. in between 0.3 mm and 2.5 mm or 3 mm, cannot be accomplished with such systems.
Further hair clippers are known from the prior art that allow an adjustment for smaller cutting length ranges, i.e. between 0.3 mm and 2.5 mm. These systems usually allow an adjustment of the position of the movable cutting blade with respect to the stationary cutting blade in order to increase the distance between these blades. Such a device is, for example known from U.S. Pat. No. 5,367,772 A.
The cutter head of this device includes a toothed stationary blade and a toothed movable blade reciprocating on the stationary blade in a hair shearing engagement between the individual toothed edges. The movable blade is slidable relative to the stationary blade in an edgewise direction perpendicular to the reciprocating motion of the movable blade for varying the haircut length. An adjustor handle is slidably fitted on an outer round surface of the housing and linked to the movable blade through a linkage member such that the movable blade is shifted in the edgewise direction to increase or reduce the cut length by rotating the adjustor handle about a longitudinal axis of the housing. A similar hair clipping device of this kind is known from U.S. Pat. No. 6,260,276 B1.
The hair clippers disclosed in the above-mentioned two prior art documents only allow a cutting length adjustment between 0.3 mm and 2 mm, up to maximally 3 mm. These devices therefore only enable an adjustment within a very small length adjustment range, and cannot be used for larger cutting lengths. This, of course, leads to a small flexibility for the user.